Pulse oximetry is used for basic instrumental examination of the cardiopulmonary system. It is non-invasive, fast and can be used continuously.
The method facilitates the decision making in starting the oxygen therapy and helps to evaluate the patient's response to it. Complex monitors of life functions (eg.
LifePack) also provide a plethysmographic curve which can further inform us about the state of the cardiovascular system. Although modern devices are capable of software compensation for movement artifacts and excessive ambient lighting the method is still limited in the case of intoxications (eg. carbon monoxide, oxidizing agents), arrhythmias, in dark ethnicities and dark nail polish.